Re: [PATCH v5] cpufreq: qcom: Read voltage LUT and populate OPP

Taniya Das
2019-01-31T17:33:00Z

On 1/23/2019 11:50 PM, Matthias Kaehlcke wrote:
> Hi Taniya,
>
> On Wed, Jan 23, 2019 at 04:52:00PM +0530, Taniya Das wrote:
>> Add support to read the voltage look up table and populate OPP for all
>> corresponding CPUS for consumers like the energy model could use the
>> frequency and voltage from the OPP tables. Also update the logic to not add
>> duplicate OPPs.
>>
>> Tested-by: Matthias Kaehlcke <mka@chromium.org>
>> Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
>> Signed-off-by: Taniya Das <tdas@codeaurora.org>
>> ---
>> drivers/cpufreq/qcom-cpufreq-hw.c | 46 +++++++++++++++++++++++++++++++--------
>> 1 file changed, 37 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
>> index d83939a..402ce81 100644
>> --- a/drivers/cpufreq/qcom-cpufreq-hw.c
>> +++ b/drivers/cpufreq/qcom-cpufreq-hw.c
>> @@ -10,18 +10,21 @@
>> #include <linux/module.h>
>> #include <linux/of_address.h>
>> #include <linux/of_platform.h>
>> +#include <linux/pm_opp.h>
>> #include <linux/slab.h>
>>
>> #define LUT_MAX_ENTRIES 40U
>> #define LUT_SRC GENMASK(31, 30)
>> #define LUT_L_VAL GENMASK(7, 0)
>> #define LUT_CORE_COUNT GENMASK(18, 16)
>> +#define LUT_VOLT GENMASK(11, 0)
>> #define LUT_ROW_SIZE 32
>> #define CLK_HW_DIV 2
>>
>> /* Register offsets */
>> #define REG_ENABLE 0x0
>> -#define REG_LUT_TABLE 0x110
>> +#define REG_FREQ_LUT 0x110
>> +#define REG_VOLT_LUT 0x114
>> #define REG_PERF_STATE 0x920
>>
>> static unsigned long cpu_hw_rate, xo_rate;
>> @@ -70,11 +73,12 @@ static unsigned int qcom_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
>> return policy->freq_table[index].frequency;
>> }
>>
>> -static int qcom_cpufreq_hw_read_lut(struct device *dev,
>> +static int qcom_cpufreq_hw_read_lut(struct device *cpu_dev,
>> struct cpufreq_policy *policy,
>> void __iomem *base)
>> {
>> u32 data, src, lval, i, core_count, prev_cc = 0, prev_freq = 0, freq;
>> + u32 volt;
>> unsigned int max_cores = cpumask_weight(policy->cpus);
>> struct cpufreq_frequency_table *table;
>>
>> @@ -83,23 +87,28 @@ static int qcom_cpufreq_hw_read_lut(struct device *dev,
>> return -ENOMEM;
>>
>> for (i = 0; i < LUT_MAX_ENTRIES; i++) {
>> - data = readl_relaxed(base + REG_LUT_TABLE + i * LUT_ROW_SIZE);
>> + data = readl_relaxed(base + REG_FREQ_LUT +
>> + i * LUT_ROW_SIZE);
>> src = FIELD_GET(LUT_SRC, data);
>> lval = FIELD_GET(LUT_L_VAL, data);
>> core_count = FIELD_GET(LUT_CORE_COUNT, data);
>>
>> + data = readl_relaxed(base + REG_VOLT_LUT +
>> + i * LUT_ROW_SIZE);
>> + volt = FIELD_GET(LUT_VOLT, data) * 1000;
>> +
>> if (src)
>> freq = xo_rate * lval / 1000;
>> else
>> freq = cpu_hw_rate / 1000;
>>
>> - /* Ignore boosts in the middle of the table */
>> - if (core_count != max_cores) {
>> - table[i].frequency = CPUFREQ_ENTRY_INVALID;
>> - } else {
>> + if (freq != prev_freq && core_count == max_cores) {
>> table[i].frequency = freq;
>> - dev_dbg(dev, "index=%d freq=%d, core_count %d\n", i,
>> + dev_pm_opp_add(cpu_dev, freq * 1000, volt);
>> + dev_dbg(cpu_dev, "index=%d freq=%d, core_count %d\n", i,
>> freq, core_count);
>> + } else {
>> + table[i].frequency = CPUFREQ_ENTRY_INVALID;
>> }
>>
>> /*
>> @@ -116,6 +125,7 @@ static int qcom_cpufreq_hw_read_lut(struct device *dev,
>> if (prev_cc != max_cores) {
>> prev->frequency = prev_freq;
>> prev->flags = CPUFREQ_BOOST_FREQ;
>> + dev_pm_opp_add(cpu_dev, prev_freq * 1000, volt);
>> }
>>
>> break;
>> @@ -127,6 +137,7 @@ static int qcom_cpufreq_hw_read_lut(struct device *dev,
>>
>> table[i].frequency = CPUFREQ_TABLE_END;
>> policy->freq_table = table;
>> + dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus);
>>
>> return 0;
>> }
>> @@ -159,10 +170,18 @@ static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
>> struct device *dev = &global_pdev->dev;
>> struct of_phandle_args args;
>> struct device_node *cpu_np;
>> + struct device *cpu_dev;
>> struct resource *res;
>> void __iomem *base;
>> int ret, index;
>>
>> + cpu_dev = get_cpu_device(policy->cpu);
>> + if (!cpu_dev) {
>> + pr_err("%s: failed to get cpu%d device\n", __func__,
>> + policy->cpu);
>> + return -ENODEV;
>> + }
>> +
>> cpu_np = of_cpu_device_node_get(policy->cpu);
>> if (!cpu_np)
>> return -EINVAL;
>> @@ -199,12 +218,19 @@ static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
>>
>> policy->driver_data = base + REG_PERF_STATE;
>>
>> - ret = qcom_cpufreq_hw_read_lut(dev, policy, base);
>> + ret = qcom_cpufreq_hw_read_lut(cpu_dev, policy, base);
>> if (ret) {
>> dev_err(dev, "Domain-%d failed to read LUT\n", index);
>> goto error;
>> }
>>
>> + ret = dev_pm_opp_get_opp_count(cpu_dev);
>> + if (ret <= 0) {
>> + dev_err(cpu_dev, "Failed to add OPPs\n");
>> + ret = -EINVAL;
>
> nit: in seems -ENODEV would be more correct, it's also what
> dev_pm_opp_get_opp_count() would return if the device had no OPP table:
> https://elixir.bootlin.com/linux/v4.20.4/source/drivers/opp/core.c#L65
>

Thanks updating it in the next patch.

>> + goto error;
>> + }
>> +
>> policy->fast_switch_possible = true;
>>
>> return 0;
>> @@ -215,8 +241,10 @@ static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
>>
>> static int qcom_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy)
>> {
>> + struct device *cpu_dev = get_cpu_device(policy->cpu);
>> void __iomem *base = policy->driver_data - REG_PERF_STATE;
>>
>> + dev_pm_opp_remove_all_dynamic(cpu_dev);
>> kfree(policy->freq_table);
>> devm_iounmap(&global_pdev->dev, base);
>
> Other than the nit about the return value:
>
> Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
>
> Also re-tested it, so the earlier Tested-by tag is applicable again :)
>
> Thanks
>
> Matthias
>

--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation.

--